Williams later changed into a floral Valentino dress before heading to Harry and Markle's nighttime reception at Frogmore House. In a relatable move, the tennis star finished the flirty, modern look with a pair of stylish black sneakers, which, as she revealed online, were also designed by Valentino's creative director Pierpaolo Piccioli.

"Little known fact: I often wear sneakers under my evening gown," Williams wrote on Instagram and Twitter. According to her social media posts, Piccioli gave the sneakers to her last minute as the tennis champion "[tends] to be comfy for long nights."

As it turns out, Williams wasn't the only person to prioritize comfort at the royal occasion.

Actress Troian Bellisario revealed on her Instagram story that guests at the evening reception were given slippers to change into if their own shoes were getting uncomfortable. Given that the royal wedding spanned the course of an entire day, these slippers were a thoughtful touch on Harry and Markle's part.